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Data on the content of benzo(a)pyrene (BP) in oil shale industry wastewater, the effectiveness of various effluent treatment processes (evaporation, extraction with butyl acetate, trickling filters, aeration tanks) in reducing the level of BP in oil shale wastewater, the level of BP in various bodies of water of Estonia, and in fish and other water organisms are reviewed. The quantitative determination of BP in concentrated diethyl ether extracts of water samples was carried out by ultraviolet and spectroluminescence procedures by use of the quasi-linear spectra at -196 degrees C in solid paraffins. It has been found that oil shale industry wastewater contains large amounts of BP. The most efficient purification process for removing the BP in oil shale industry phenol water is extraction with butyl acetate. The level of BP in the rivers of the oil shale industry area is comparatively higher than in other bodies of water of the Republic. The concentration of BP in the lakes of the Estonian S.S.R. is on the whole insignificant. Even the maximum concentration found in our lakes is as a rule less than the safety limit for BP in bodies of water (0.005 microgram/l). During water is treated at the waterworks. The effectiveness of the water treatment in reducing the level of BP varies from 11 to 88%. Filtration was found to be the most effective treatment. About 20 samples of fish from nine bodies of water in Estonia have been analyzed for content of BP. The average content of BP in the muscular tissue of various species of fish is as a rule less than 1 microgram/kg. There is no significant difference in the concentration of BP in sea and freshwater fish. There is no important difference in the content of BP in the organs of various fish. Fat fish contain more BP than lean ones. The weight (age) of fish does not influence the content of BP in the muscular tissue of fish.

Polycyclic aromatic compounds continue to be regarded as a major environmental threat, especially in the aquatic environment. To gather further information on the distribution and levels of these persistent organic compound in natural waters, the current analytical study was carried out. Material collected from multiple sites within the coastal and open sea areas of several surface water bodies had different levels of polycyclic aromatic compounds. Concentrations of dissolved, particle- and biota-associated compounds (i.e., benzo (a)pyrene, benzo(e)pyrene, pyrene, chrysene and so on) were measured by multiple analytical techniques. The sediment and biota samples were extracted using Soxhlet extraction followed by analysis using reverse-phased liquid chromatography with ultraviolet and fluorescence detection and high resolution luminescence spectroscopy. This group of pollutants was significantly enriched in particulate matter, sediments and biota material at all sites relative to water concentrations. On the basis of data obtained, the enrichment factors of 10 to 105 for different carcinogenic and noncarcinogenic compounds in the particulate material and biota are reported. Higher concentrations of the more hydrophobic compounds were found in sediments. Thus, the bottom biota may be exposed to higher levels of hydrophobic pollutants than organisms residing in the upper sediment-water interface.